The Voyager 2 spacecraft launched #OTD in 1977.
It is currently 12.4 billion miles from Earth, hurtling through interstellar space at about 34,400 mph with respect to the sun.
Voyager 2 is so far from Earth that round trip for signals is 36.5 hours.
Only its twin Voyager 1 (which launched a few weeks later, but took a more direct route out of the solar system) is further.
Image: NASA/JPL-Caltech